import math

x1, y1, x2, y2 = list(map(float, input().split()))

exp_dist = abs(x1 - x2)**2 + abs(y1 - y2)**2

print(math.sqrt(exp_dist)) import math math x1, y1, x2, y2 = list(map(float, input().split())) x1 list(map(float, input().split())) list map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 exp_dist = abs(x1 - x2)**2 + abs(y1 - y2)**2 exp_dist abs(x1 - x2)**2 + abs(y1 - y2)**2 abs(x1 - x2)**2 abs(x1 - x2) abs x1 - x2 x1 x2 2 abs(y1 - y2)**2 abs(y1 - y2) abs y1 - y2 y1 y2 2 print(math.sqrt(exp_dist)) print math.sqrt(exp_dist) math.sqrt math sqrt exp_dist y1, x2, y2 = list(map(float, input().split())) list(map(float, input().split())) y1 x1, y1, x2, y2 = list(map(float, input().split())) list(map(float, input().split())) x1 y2 = list(map(float, input().split())) list(map(float, input().split())) y2 x2, y2 = list(map(float, input().split())) list(map(float, input().split())) x2 exp_dist = abs(x1 - x2)**2 + abs(y1 - y2)**2 abs(x1 - x2)**2 + abs(y1 - y2)**2 exp_dist
import math

x1, y1, x2, y2 = list(map(float, input().split()))

exp_dist = abs(x1 - x2)**2 + abs(y1 - y2)**2

print(math.sqrt(exp_dist))